Prolonging Bacterial Viability in Biological Concrete: Coated Expanded Clay Particles

Area of Science:

• Civil Engineering
• Materials Science
• Microbiology

Background:

• Ensuring long-term bacterial viability in biological self-healing concrete is a significant developmental challenge.
• Bacteria are crucial for the self-healing properties of concrete, but their survival within the harsh concrete matrix is limited.
• Novel carrier materials are needed to protect embedded bacteria and maintain their viability over extended periods.

Purpose of the Study:

• To investigate the efficacy of coated expanded clay (EC) as a carrier for bacteria in biological self-healing concrete.
• To evaluate the long-term viability of bacteria encapsulated within different EC coatings.
• To correlate bacterial viability with the crack healing performance of the developed biological concrete.

Main Methods:

• Eight different coating materials were applied to expanded clay (EC) particles.
• Coated EC particles were incorporated into concrete mixtures as bacterial carriers.
• Long-term bacterial viability was assessed over 56 days.
• Crack closure ratios were measured to evaluate healing efficiency in biological concrete specimens.

Main Results:

• The study found a strong correlation between the number of viable bacteria and the healing efficiency of biological concrete.
• Specimens with higher viable bacteria counts demonstrated superior crack closure.
• Coated expanded clay (EC) particles significantly improved the long-term viability of embedded bacteria.
• The evaluated coating materials varied in their effectiveness in preserving bacterial viability.

Conclusions:

• Coated expanded clay (EC) is a promising carrier material for enhancing long-term bacterial viability in biological self-healing concrete.
• Improved bacterial viability directly translates to more efficient crack healing in concrete.
• The selection of appropriate coating materials is critical for optimizing the performance of biological concrete.